The subject invention relates to a new and improved automatic lock bottom carton with a pyramid closure having two tabs extending from two panels that lock into corresponding openings on tabs of oppositely presented panels. The carton is formed from a planar sheet of paperboard blank and includes an auto-erecting lock bottom which enables the carton to be shipped from the manufacturer in a flattened condition. The closure includes a double lock which prevents the collapsing of the pyramidal shape once erected so it can support a product and maintain it in its intended form. An example of such a product would be contoured nursing pads which when made from soft material must be packaged in a manner which will retain their concave-convex shape.
The carton of the invention can be of a single cell structure or a multiple cell structure with a pyramid closure in each cell and a center divider between the cells. In this type of carton one of the pyramid sides is derived from the center divider.
Various cartons in the prior art have been provided with a pyramid closure. It has been found, however, that the higher the vertex of the pyramid is from its base, the more positively it stays formed. When a vertex of a pyramid is low or shallow from its base the pyramid has a tendency to collapse to become flat and to lose its form, so that what is left is basically a flat standard automatic locked end. The present invention solves this problem by having two tabs from two panels locking into corresponding openings in two opposing panels, thus preventing the collapsing of the pyramidal shape and supporting the product in its intended form.